1) Field of the Invention
This invention relates to a magnetic closure which connects flexible or also fixed elements with each other, such as e.g. a closure on a handbag.
2) Description of the Prior Art
From the prior art magnetic closures are known, which attract each other on closing, but are rotated or shifted against each other for opening. These closures have the advantage that they can be opened more softly as compared to the case where the closure has to be pulled apart in the same direction in which it contracts on closing. Such a magnetic closure is described in the document DE 196 42 071 A1. In this construction, the armature is completely pushed off from the magnet during the opening movement, so that closures of this type can be opened almost without force.
However, such closures often have no optimum haptics, wherein haptics is understood to be the property of how a closure feels when opened, but also when closed, if it is actuated manually. The cause for such poor haptics is the fact that upon complete separation of the closure halves a rest of the magnetic force mostly has yet to be overcome, so that a jerky haptics is obtained, as in contrast to the structure from DE 196 42 071 A1 sufficient shifting path is not always available for laterally shifting armature and magnet, until the magnetic force acting between armature and magnet is almost zero. Therefore, the last opening movement must be effected opposite to the closing movement.
To overcome this deficiency, magnetic closures are known from the prior art, which operate according to the principle of the polable magnet systems. By rotating or shifting the magnet systems against each other, i.e. when performing the opening movement, the magnet systems are moved into a mutually repelling opposed position. Opening the closure thereby is supported comfortably, and the haptics is distinctly improved. However, these closures are expensive in production, since a multitude of magnets or expensive multi-pole magnetizations of the magnets are required.
An improvement of the haptics on closing of a magnetic closure is described in the document DE3631092. There is provided a spring which is arranged between armature and magnet, and after closing generates a force directed opposite to the magnetic field, in order to reduce the impact noise on closing. Despite the advantage achieved on closing, this closure has no good haptics on opening, as it must be separated with a strong jerk. The reason for this is that the magnet is separated opposite to the closing direction and thus has the typical jerky force characteristic of a magnet with maximum force of attraction in closing position and strongly non-linearly decreasing force of attraction with increasing distance of armature and magnet.